1. Field of the Invention
The present invention relates to a resending control circuit, a resending control method and a resending control program, whereby resending of data to be sent to a sending destination is controlled.
2. Description of the Related Art
Commonly, under a wireless communication environment, a sending error or the like occurs during sending of data to be sent (hereafter, referred to as “sending data”), and a situation wherein none of the data to be sent reaches the reception side frequently occurs. Therefore, with a communication device for performing wireless communication, for example, a resending function such as the communication device disclosed in Japanese Patent. No. 3011159 (hereafter, a circuit for realizing this function is referred to as “resending control circuit”) is provided, and accessibility of sending data is secured. As for a communication device including this kind of resending function, for example, there is a communication device disclosed in Japanese Patent No. 3011159. With the communication device disclosed in Japanese Patent No. 3011159, resending point-in-time, resending destination, and so forth corresponding to sending data that has already sent are stored in memory, a register, or the like as resending information, and are managed, and resending processing is executed based on this resending information.
Now, description will be made regarding resending processing that is executed by an existing resending control circuit with reference to FIG. 10. First, a resending control circuit 200 illustrated in FIG. 10 includes multiple registers 201 storing resending information (e.g., made up of resending point-in-time, a resending destination, and so forth corresponding to sending data that has already sent) for each resending destination (node), and multiple comparing units 202 for performing comparing processing for each of the multiple registers 201. The resending control circuit 200 reads out all of the resending information stored for each of the registers 201 with a predetermined time interval, compares the readout resending information with the current point-in-time at the comparing units 202, and determines regarding whether or not the current point-in-time has passed resending point-in-time. Subsequently, in the event of determining that the current point-in-time has passed the resending point-in-time, the resending control circuit 200 outputs a resending processing trigger to predetermined sending processing means. Subsequently, upon a resending processing trigger being input, the sending processing means start resending processing.
Next, a resending control circuit 300 illustrated in FIG. 11 includes memory 301 storing resending information for each region allocated for each address Addr, a reading unit 302 reading out resending point-in-time TxTime from the resending information stored in each storage region, and a comparing unit 303 performing comparison processing for comparing the resending point-in-time TxTime read out by the reading unit 302 with the current point-in-time. With the resending control circuit 300, the reading unit 302 reads out all of the resending information stored in the memory 301 for each predetermined time interval, and the comparing unit 303 compares the readout resending information with the current point-in-time, determines regarding whether or not the current point-in-time has passed the resending information, and outputs a resending processing trigger.
Also, in response to an ACK signal from a sending destination received by receiving means included in the communication device, the resending control circuits 200 and 300 perform for deleting the resending information that is unnecessary for resending from the registers 201 and memory 301.